HI.
The El Al missile defense system would not provide defense against an unguided rocket that just happens to hit a plane on the ground (or in the air for that matter). El Al missile defense is against infrared guided missiles.
The Hammas Rockets are unguided and just pointed in a direction and they land where they land and boom. They might hit the airport or an airplane or they might hit a delicatessen or a movie theatre.
I do understand that the IRON DOME system costs 20,000 dollars per intercept. IRON DOME works against artillery or unguided rockets. TO MY KNOWLEDGE it would not stop a MANPAD.